There have been widely used reciprocating tools which move tip tools in reciprocation directions and perform work such as cutting. As examples of these reciprocating tools, jigsaws are known. A tool for converting a rotation of a motor or the like into a reciprocation of a tip tool according to the related art will be described on a basis of an example of the jigsaws and with reference to FIG. 7.
FIG. 7 is a partial cross-sectional view of a jigsaw 101 according to the related art. The jigsaw 101 includes a motor (not shown), which is accommodated in a housing 115, and a pinion 113 that is provided to an output shaft 109 of the motor. The pinion 113 is engaged with a gear 107 which is provided with an eccentric cam 107a that is configured to make a balance weight 108 reciprocate. Also, an eccentric pin 111, which is configured to make a plunger 112 reciprocate, is provided to the gear 107. A reciprocating motion converter is used to convert the rotation of a rotary drive source (e.g., the motor) into the reciprocation of the plunger 112, so as to cut a workpiece with a blade 114 attached to the lower end side of the plunger 112. Also, according to the reciprocation of the plunger 112, the balance weight 108 reciprocates in the opposite phase to that of the plunger 112, thereby compensating for vibration attributable to the reciprocation of the plunger 112. As this jigsaw 101, a technology disclosed in PTL 1 is known. In this related-art technology, an elastic member 121 is interposed between a gear holder 105 (a part of the reciprocating motion converter) and a housing 115, so as to reduce transfer of vibration occurring at a blade 114 to a housing 115.